In existing broadcast television systems, broadcast signals are broadcasted in both digital and analog format. The digital format contains similarities to existing and well-known analog broadcast formats, but further includes added information and channel bandwidth, among other benefits. For example, an analog signal transmits a single channel dedicated to a specific frequency range. Therefore, for a dedicated frequency range, a tuner tunes a single channel.
In the digital domain of video broadcasting, the digital format allows the embedding of multiple channels for a single frequency dedicated channel. Typically, the frequency dedicated channel is referred to as a major channel and the embedded multiple channels are referred to as minor channels. For example, in the analog system, channel 41 would contain a single television station broadcast, such as a local television station affiliated with a national broadcaster. Although, a digital television broadcast may have multiple channels associated with the dedicated channel 41. For exemplary purposes only, digital broadcast channel 41 may include a first channel, which is a high definition format of the local television station, a second channel that includes weather information and a third channel that is associated with the affiliated national broadcaster.
In the current digital broadcast technology, users are required to use a multi-part channel numbering system. A first set of numbers is directed to the major channel, such as channel 41. A second set of numbers is then directed to the minor channels, such as channels 41-01, 41-02 or 41-03. Therefore, users are required to learn a whole new channel numbering system and are also required to further input a total of five inputs, including the “-” to select a channel.
Another approach is to default a user to the major channel upon entering the first set of numbers. Using the above example, if the user enters channel 41, the tuner is defaulted to displaying channel 41-01. The user may then toggle using up and down buttons to move between channels 41-01 and 41-03.
In the analog broadcast system, channel switching techniques exist wherein a user is allowed to preview multiple channels at a single time. In one embodiment, multiple tuners allow for a picture in picture viewing mode, wherein multiple screens display different outputs, in accordance with well-known picture in picture techniques. Although, picture in picture is inherently limited based on needing a separate tuner for each of the different pictures. Therefore, in a system having the ability to provide picture in picture display, a second tuner is required. For a system in the analog format to have more than a picture in picture viewing scenario, multiple tuners would be required. Adding tuners not only requires further processing overhead and power requirements, but also adds to the overall space of a processing device as well as significant costs increases for the multiple tuners.
Another analog approach for multiple channels is to provide still-picture thumbnails of multiple channels. This approach requires the use of thumbnails for multiple channels due again to the limitations of needing separate tuners for multiple signals. In this approach, the tuner may be adjusted to a particular channel for a period of time to acquire of a thumbnail of the display, typically a single frame of image data. The tuner may then be advanced to the next channel to acquire another frame of image data. This process is continued in a rolling fashion, updating thumbnails and allowing for a single screen visual view of multiple channels. Although, this approach is limited to only still pictures of existing channels and requires extensive processing to cycle the tuner through different channels and update the thumbnails on a continuous basis.
Therefore, there exists a need for the navigation of multiple minor channels of a digital video broadcast signal.